We have just returned from holiday.
We used...
Randox LFTs for return pre departures... got certificates through in under a minute of submitting scan. However App was complex to download.
Randox 2 day PCRs... did yesterday afternoon. Again the registering system was a pain. However we dropped them in the box at 4pm yesterday, results by 8am this morning.
Chromatics Day 2 PCRs... registering more straightforward. Used the Royal Mail return envelopes (as we couldn't get near a drop box). Posted yesterday at 2pm. Will update when we recieve results.